#chapter{
  .banner{
    position: relative;
    .focus_img{
      width:100%;
      height: 3rem;
      overflow: hidden;
      background: url("/images/pc/study.jpg") no-repeat;
      background-size: 100%;
      background-position-y: -2.5rem;
      &::before{
        content:"";
        position: absolute;
        top: 0;
        right: 0;
        bottom: 0;
        left: 0;
        background:linear-gradient(180deg,rgba(0,0,0,.2) 70%,#000);
      }
    }
    .book_title{
      position: absolute;
      color: #fff;
      font-size: .4rem;
      font-weight: 800;
      left: .3rem;
      bottom: .3rem;
    }
  }
  .menu{
    width: 100%;
    border-top: 1px solid #ccc;
    background-color: #fff;
    .jumap{
      width: 100%;
      height: 0.85rem;
      border-bottom: 2px solid #f0f0f0;
      display:flex;

    .button{
      width: 1.1rem;
      height: 0.83rem;
      font-size: 0.28rem;
      background-color: white;
      border: white;
      border-bottom: 2px solid white;
      flex:1
    }
    }
    .fold{
      width: 100%;
      .chapter-item{
        display: flex;
        justify-content: space-between;
        align-items: center;
        padding: 0 .5rem;
        width: 100%;
        height: 64px;
        list-style: none;
        border-bottom: 1px solid #ccc;
        font-size: 20px;
        i{
          transition: .3s all ease-in-out;
          font-style: normal;
        }
      }
    }
    .sections{
      width: 100%;
      display: none;
      background-color: #fff;
      a{
        text-decoration: none;
        .section-item{
          width: 100%;
          height: 1rem;
          padding: .3rem 1rem;
          color: #7e7e7e;
          font-size: .3rem;
          border-bottom: 1px solid #ccc;
        }
      }
    }
    .introduce{
      display: none;
      padding: .2rem;
      .introduce_title{
        font-size: .4rem;
        margin-bottom: .1rem;
      }
      .introduce_content{
        font-size: .3rem;
        color: #ccc;
      }
    }
  }
}